[GLLUG] Electronics - Wii Remote on Linux

[Jason Watson]

If my memory serves me right, IR LED's usually have a smaller voltage
drop (~1 - 1.5V) compare to common red LED's (~2V).  You'll need to
wire a resistor in series with the LED to limit current and to drop
the excess voltage from your supply.  More current will give you more
brightness up to the spec'd limit of the LED (more than that and
you'll decrease the life of the LED or completely smoke it).  20 -
25mA is usually a good round and safe target to start out with.
Assuming you are using a 9V batt for the supply and the LED drops 1V
that leaves you with 8V dropped across the resistor.  8V / 20mA gives
you a 400 ohm resistance value.  390 or 430 ohm 1/4 watt are the
closest standard resistor values.

On 4/25/07, Richard Houser <rick at divinesymphony.net> wrote:
> You said you pulled this out of a Universal Remote, correct?
>
> I doubt that remote would be stepping up the voltage, so I think you are
> probably looking at ranges of 2.4-3.0V, 3.6-4.5V, or 4.8-6.0V max in use
> on the remote depending on the number of batteries it has in series.
>
> If you can't find what the part number is, you might be able to just
> hook the IR LED back up to the remote and measure the voltage placed
> across the leads with a scope (if it's not obvious from the circuit).
> The LED might very well be 9-12V, but putting too much voltage on or
> current through an LED will fry it.  You'll probably need a resister
> even if the voltage is right, just to keep the current down (unless that
> unit one has one built-in).
>
> Karl Schuttler wrote:
> > Well, I managed to buy a cheap <$15 usb bluetooth adapter, and have
> > gotten my control interfacing within linux with the linux driver. In
> > order to complete this, I need a few IR LED's in order for the remote
> > to calculate its position. I ripped two of these out of the same model
> > RCA television remotes that I got at staples for free with rebate, and
> > now I'm wondering if it is okay just to wire them series to a 9 volt
> > battery. Any ideas?
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